Electric cut-out switches



Oct.23, 1956 G. ALLARD 2,768,262

ELECTRIC CUT-OUT SWITCHES Filed May 17, 1955 2 She'ets-Sheet 1 Oct. 23,1956 G. ALLARD ELECTRIC CUT-OUT SWITCHES Filed May 17, 1955 2Sheets-Sheet 2 ELECTRIC CUT-OUT SWITCHES Georges Allard, Bois-Colombes,France Application May 17, 1958, Serial No. 509,028

Claims priority, application France May 31, 1954 20 Claims. (Cl.200-116) The present invention relates to an improved electric cut-outswitch adapted to break in a very quick and safe manner the circuit inwhich it is interposed, this breaking action occurring eitherautomatically or under the influence of external control means.

A switch of this type is already known which is adapted to operateautomatically under the influence, for example, of a predeterminedcurrent characteristic and comprises a fixed contact and a movablecontact responsive to the action of a resilient force tending to movethese contacts away from each other.

In a former patent the applicant has described a switch of the typebroadly set forth hereinabove wherein the movable contact was carried byan arm or lever adapted to effect in its plane a movement of rotationand a movement of translation, both of which taking place in directionssuch as to move the movable contact toward or away from the fixedcontact, this arm being urged by a resilient force tending to move thecontacts away from each other, and bearing with its end opposite to thatcarrying the movable contact against a movable stop member retractableat will upon variation of a predetermined current characteristic, saidarm being adapted to be held against motion in its contact-makingposition by a releasable locking device adapted when released toautomatically disengage said arm due to the rocking movement thereof.

Now it is the object of the present invention to provide a switch ofthis type but improved in that it is particularly simple and extremelysafe in operation. This switch is remarkable notably in that itcomprises a control member such as a push-button, rocking lever or thelike, actuated from the outside and acting upon said arm against theaforesaid resilient force through a projection, point, blade or the likeabout which the arm is adapted to rotate during its contact-making andcontact-breaking movements, the lower portion of this member carrying,or being associated with, a catch or the like adapted during thecontact-making movement to engage a movable and independent lockingmember so that the catch of the arm may be either held against motionupon completion of the contact-making movement, due to the rocking ofthe locking member, or released during the contact-opening movement dueto the reverse rocking movement of this locking member which is inducedby the rotation of said arm about said catch or the like.

According to another feature of the present invention, the aforesaidlocking member consists of an L -shaped lever turned upside down andpivoting about its lower end, a resilient member for example a spring,urging the lever in its locking position against the catch carried bythe control member.

Other features and advantages of the invention will appear as thefollowing description proceeds with reference to the accompanyingdrawings forming part of this specification and illustratingdiagrammatically by way of exnited States Patent i 2,768,262 PatentedOct. 23, 1956 ample a preferred form of embodiment of the invention. Inthe drawings:

Figure 1 is a longitudinal vertical section of a cut-out switch shown inits contact-making position;

Figure 2 is an elevational and part-sectional view of the same devicebut in its contact-breaking position;

Figure 3 is a longitudinal section of the device during acontact-breaking movement;

Figure 4 is a section taken upon the line IV-IV of Fig. 2, and

Figure 5 is an isometric view showing the apparatus with the casingremoved for the sake of clarity.

In the preferred embodiment shown in the drawings the switch accordingto this invention comprises a casing 1 and a base 2 supporting theswitch mechanism. The latter comprises a fixed contact 3 and a mainmovable c0ntact 4 rigid with an arm 5 consisting, for example, of aplurality of resilient blades 5', 5", 5" fastened to each other by arivet 43. The intermediate blade 5" carries the main movable contact 4and the upper blade 5' carries an auxiliary movable contact 4' acting asa sparkarrester. This arm 5 is urged by a spring 6 to a contactopeningposition and adapted to be actuated by a contactmaking member 7, forexample of the push-button type. Of course, the push-button 7 may bereplaced by any other suitable control member, for example ahand-actuated pivoting lever or the like. This button 7 carries a plate8 rigid therewith and formed with a pair of depending projections orlugs 9 and 10; the projection 9 is surrounded by the spring 6 and theprojection 10 is adapted to co-act with a locking member 11.Intermediate these projections the plate 8 is formed with a knife-edgeprojection 12 adapted to engage the arm 5, the latter being adapted topivot about the central projection 12 due to the provision of notches ororifices 13, 14 formed in the blades 5, 5", 5" through which theprojections 9 and 10 extend as shown.

The lower portion of the projection 10 is formed with a notch 15 and acatch-forming lug 16, adapted to co-act with a corresponding lug 15 andnotch 16' formed in a locking member 11 having the shape of an invertedL. This locking member 11 is pivotally mounted through a pin 17 on thebase 2 and normally urged to the position of Fig. 1, i. e. in its lockedposition, by a compression spring 18 bearing with one end against thelower end of the locking member 11 and with its other end against asuitable projection 19 of the base 2.

The arm 5 engages with its rear end, i. e. the end opposite to thatcarrying the movable contacts 4, 4', a movable stop member 20 consistingof a separate blade the lower portion 21 of which engages a notch 22formed in the base of the apparatus.

The stop member 20 adapted to rock relative to the base 2 is normallymaintained in the position shown in Fig. 1 by means of a tension spring23 anchored at one end 24 to the base of the switch and at its other end25 to the blade 20, this other end 25 being for example of ring shape soas to be hooked in a projection 26 of the blade 20 to urge the latteragainst the edge 34' of a flange 34. The upper portion of the blade 20has a notch 27 formed therein which is adapted to be constantly engagedby the rear end of the arm 5, and a curved portion 28 adapted to bedepressed by the lower portion 29 of a contact-releasing memberprojecting from the switch casing and consisting in this example of apush-button 30.

The blade 25% is also formed with a bent lug 31 having a heel 32 adaptedto be engaged by the upper portion of a bimetallic strip 33 having twosides 33, 33" and responsive for example to any overload characteristicsof the circuit or to any other predetermined external characteristicwhich is to constitute the circuit-breaking factor.

The blade or movable stop member 20, instead of being independent,mayalsolbe pivotally mounted at its. lower end'Zl' through a suitablepivot pin, by, means of trunnions or the like,engaging,correspondingorifices formed in the base 2. 7

A pairofwalls 34, 35 (see Figs. 2 and .4) disposed on either side of thearm 5, i. e. in front of and behind the plane 'of Fig. lyconstitute akind of channel adapted to guide the arm during thermovements oftranslation and rotationthereof, so that these. movements take placesubstantially in a same plane, parallel to these walls. Moreover, thesewallsform a contact breaking. chamber and insulate the contacts fromtheother portions of .the device. These. walls may be formed integrally,for ex- .arnple by casting or machining, with the base 2, the lat terconsisting preferably of plasticinsulating material.

There is shown M736 a; flexible conductor connecting the arm 5 to thesider33 of the blade 33, the other side 9 of this blade beingelectrically connected to the terminal 'or. stud 37.

' The arm 5 comprises a lateral projection or lug 38 (see Figs; 4 and 5)which may be formed integrally with its central portion and adapted toengage a slit 39 formed in the side wall 34-to prevent the arm 5 frommoving in th longitudinal direction. This lug 38 may, as shown in Fig.5, serve as a means for closing a circuit separate from the main circuitby means of auxiliary contacts 49,

"4%)" and of a transverse blade 41 carried by a plate '42. An

orifice '42Gformed in this plate is adapted to be engaged by the lug 3%of the arm 5 so as to carry along the blade '41 in itsverticalmovements.

"The device described hereinabove operates as follows: pAssumingtheapparatus to be in its released or opencontact condition (Pig; 2) thecontacts may be'closed by depressing the control push-button 7. Duringthis downward movement the knife-edge 12 of the plate 8 rigid with j thepush-button 7 engages the arm 5 and as the latter engages the 'notch'27in the blade 20 it rotates thereabout until the movable contacts 4, 4Tcarriedbythe arm 5 engage the'fixed contact 3. During this pivotingmovement of the arm 5 the push-button 7 is further depressedauditsprojection it engages the L-shaped lockmember "11 so asto'slightly rock sameabout its pivot pin 17, but --the-return spring l8associated'therewith will finallyrestore'the locl; member .11 totheposition in which it is 16. registering. with each other.

shown i'nil-ig. 1,;with the notches and lugs'15, and 16, Theseconditions are attained when the contacts engage each: other, .so; thatthe push-button I will be locked in its lower-most position by thelocking member 11; on the other hand, the pushbutton 7 will lock the arm5 in its contact-making position by means of its knife-edge portionlZ.The pressure between the movable'contacts 4, i and the fixed contact 3is obtained for example by employing resilientblades 5 and 5". 4 Withthe cut-out switch in its contact-making condition the current flowsfrom the input pin .44 through .the fixed contact 3, movable contacts 4,4, arm 5, flexible conductor 36, side 33 of bimetallic stud 37 to outputpin 45.

The movable stop member of the bimetallic strip strip 33, side 33",

'33 may be readily insulated by interposing for example a plateof micaor like material between the upper portion of'blade33 and the heel'32'of the stop member on which it is adapted to act.

[If nowthe stop member 2% is moved aside by depressing therelcase button3t or if the same effect is produced by the expansion of the bimetallicstrip 33 due to the outeach other. During this rocking movement theblade 5",

which may be relatively rigid, will be the first element to rotate so asto impinge against the blade 5 with its end opposite to the one engagingthe stop member 20. Practically, these movements take place nearlysimultaneously, but a certain delay is introduced however which causesthe main contact 4 to open before the auxiliary contact 4. As a result,in case of circuit overload the contact-breaking action is efiectiveonly when the auxiliary contact 4 leaves the fixed contact so as toavoid arcing in the operation of the device, the contact arrangementoperating as a sparking-arrester.

On the other hand,-the striking of the blade 5" against the blade 5 andof the blade 5" against 5' will provide a snap effect in thecontact-breaking operation.

When the arm deflects its contact-breaking movement it knocks againstthe upper member of the L-shaped lever Iii and the latter is also rockedin the clockwise direction, thereby releasing the catch 16 on theprojection 10.

Then the push-button 7 will be restored to its upper position v(Fig. 2)by the'spring 6 urging the arm 5 and thereforethe knife edgelZ upwards.During this upward movement the lug 38 will carry along the transverseblade .41, therebyopening the auxiliary circuit by separating thecontact-carrying arms 40, 40 from each other. Of course, it isalsopossible to combine the closing of the auxiliary. circuit with theopening of the main circuit, and vice-verse, according to the sameprinciple.

It will be readily understood by anybody conversant with the art. thatthis switch is particularly safe and efiicient in operation, for if apressure is exerted on the pushbutton 7 as the release takes place, thearm 5 may still rock about the knife edge 12 and carry along the movablecontact 4 to separate it from the fixed contact 3. This rocking movementtakes place freely, since the orifices 13, 14 are properly dimensionedto avoid any frictional engagement between the arm and the relevantfaces of the two projections h, it) of plate 8.

Onthe other hand, it will be seen that due to the relatively low numberof parts required in its mechanism the manufacture of cut-out switchesaccording to this invention is particularly economical.

Thus, all the elements projecting from .the base may be formedintegrally therewith in a single moulding operation.

Besides, the assembling anddisassembling of the cutout switch will befacilitated to a substantial degree if the spacing between the arms 9,it) and the actuating button 7, on the one hand, and the size of theorifices 13, E4, on the other hand, are calculated to permit anunobstructed sliding movement of the push-button 7 so as to free itcompletely from the arm 5. From'the foregoing it is apparent that themain component parts of the device, i. e. the push-button 7, arm 5 andstop member 20, are completely independent of one another as well 'as ofthe base or casing of the switch; therefore, their replacement may beeffected veryquickly, without interout departing from the spirit andscope of the invention.

Of course, this invention is not restricted to the single form ofembodiment shown and described herein by way of example, asmanymodifications maybe brought thereto without departing from theprinciples of the invention as set forth in the appended claims.

What I claim is:

l. An electric switch the contact breaking action of which-.occursundertheinfiuence of an external control action comprising a fixedcontact and a cooperating movable contact, slidable androtatable levermeans carrying at one end said movable contact, movable stop meanssupporting the other end of said lever means in the on" position,resilient means acting on said lever means to rotate said lever means tothe ofi position when said movable stop means is deflected, a manuallyoperable contact making member with projecting pivot means acting onsaid lever means for moving said movable contact into the on position,projections means carried by said contact making member and lockingmeans cooperating with said projections means for keying said contactmaking member and said lever means at the end of the rotating closingmovement of said lever means said locking means being adapted to beactuated and to release automatically said projection means when saidlever means rotates to the off position around said projecting pivotmeans.

2. An electric switch the contact-breaking action of which occurs underthe influence of an external control action comprising a fixed contactand a cooperating movable contact, slidable and rotatable lever meanscarrying at one end said movable contact, movable stop means supportingthe other end of said lever means in the on position, resilient meansacting on said lever means to rotate said lever means to the oilposition when said movable stop means is deflected, a manually operablecontact making member with projecting pivot means acting on said levermeans for moving said movable contact into the on position, projectionsmeans carried by said contact making member, a cranked arm pivoted atits lower end and acted upon by a resilient means for cooperating withsaid projection means in the on position and keying said contact makingmember and said lever means at the end of the rotating closing movementof said lever means said cranked arm being adapted to be actuated and torelease automatically said projection means when said lever meansrotates to the off position around said projecting pivot means.

3. An electric switch according to claim 2 wherein said projection meansof said contact making member are constituted by lug means provided withcatch means cooperating with said crancked arm in the locked posi tion.

4. An electric switch according to claim 2 wherein said cranked armcomprises an upper side adapted to be engaged by said lever means duringthe movement of rotation thereof which moves the contacts away from eachother, so as to cause the pivoting of said cranked arm in the directionensuring the release of said projec tion means.

5. An electric switch according to claim 2 wherein the resilient meansconsists of a spring acting on the lower side of said cranked arm andconnected at its opposite end to a fixed part integral with the switchbase.

6. An electric switch according to claim 3 wherein contact-making membercomprises another lug means surrounded by said resilient means acting onsaid lever means.

7. An electric switch according to claim 6 wherein said lug means aredisposed on either side of said projecting pivot means of saidcontact-making member.

8. An electric switch according to claim 2 wherein said projecting pivotmeans consists of a knife integral with said contact-making member.

9. An electric switch according to claim 2 wherein said resilient meansacting on said lever means is a compression spring acting at one pointof said lever means which is located between the movable contact and therocking axis of said lever means.

10. An electric switch according to claim 9 wherein said spring isadapted to cause said contact-making member to move upwardly after thelatter has rocked said cranked arm at the end of its release movement.

11. An electric switch according to claim 2 wherein said projectionsconsist of blades passing through slots, orifices or the like formed insaid lever means.

12. An electric switch according to claim 2 wherein said lever means isindependent of the contact-making member and is guided in its movementsof translation and rotation by a pair of flanges substantially parallelto said movements.

13. An electric switch to claim 12 wherein said lever means comprises aprojection slidably engaging a groove substantially parallel to itsdirection of translation so as to limit the displacement of said levermeans perpendicularly to said direction of translation.

14. An electric switch according to claim 13 wherein said projectioncontrols, by means of a beam means driven thereby, the closing andopening of an auxiliary circuit, for example a signal circuitindependent of the main circuit.

15. An electric switch according to claim 14 wherein said projectionacts upon the said auxiliary circuit so that its opening and closingwill be coincident with the opening and the closing of the main circuit.

16. An electric switch according to claim 12 wherein said flanges arerigid with the switch base and consist preferably of insulatingmaterials.

17. An electric switch according to claim 2 wherein said stop elementconsists of a blade adapted to pivot about its lower portion and held incontact-making position by resilient means.

18. An electric switch according to claim 17 wherein said blade isindependent of the switch base and is simply inserted through its loweredge in a groove, slot or the like formed in said base.

19. An electric switch according to claim 18 wherein said blade carriesat its upper portion hooking means on which a bimetallic stripcontrolled from the outside is adapted to act in a direction such as torelease the stop element from the lever means carrying the movablecontact.

20. An electric switch according to claim 2 wherein a plurality of fixedand movable contacts are provided in order to render said switch of themulti-pole type.

References Cited in the file of this patent UNITED STATES PATENTS2,701,829 Krieger Feb. 8, 1955 FOREIGN PATENTS 1,034,820 France Apr. 15,1953

